1. Field of the Invention
The present invention relates to an image display device and method, and to an image communication apparatus and method.
2. Description of the Related Art
As a result of diffusion of computer networks such as Internet, it is becoming practically possible to transmit even image data on a computer network, although some problems still exist in resolution, the transmission rate and the like.
In the general configuration of an image data base, an image file server and a client are connected to a network, and the image file server transmits assigned image data to the client in response to a request from the client. By interactively operating a computer, serving as the client, the user can display an arbitrary image stored in the image file server on a monitor of the computer.
For example, as shown in FIG. 1, a summary of image data stored in an image file server is displayed on a client""s monitoring picture surface. In FIG. 1, reference numerals 20-28 represent schematic images for displaying an outline of the image data stored in the image file server. By selecting one of the displayed schematic images 20-28, the user selects a desired image data.
The schematic images 20-28 are subjected to hierarchical encoding, for example, according to a JBIG (Joint Bi-level Image Group) method which is an international standard encoding method. Since hierarchical encoding can decode a plurality of images having different resolutions from one image data, it is suitable for a use in which it is intended to decode a plurality of images having different resolutions. Conventionally, in order to display schematic images on a client""s monitoring picture surface, hierarchically encoded image data is decoded in accordance with the resolution of the picture surface.
The band of a computer network greatly changes in accordance with a change in the state of use of other users, the configuration of the network (for example, switching from a wire LAN (local area network) to a radio LAN), or the like. Since preparation of means for securing a necessary band width is insufficient, it is generally impossible to secure the necessary band width.
When the band is narrowed as a result of a change in the band width as described above, the response time may, in some cases, extremely increase due to a decrease in the transfer rate of encoded data, so that it is necessary to wait for a long time for displaying schematic images.
It is an object of the present invention to solve the above-described problems.
It is another object of the present invention to provide an image display device and method, and an image communication apparatus and method, in which a necessary image can be retrived more promptly.
It is still another object of the present invention to realize efficient image-data processing by transmitting and displaying image data in consideration of a transmission speed of a network.
It is yet another object of the present invention to provide new functions.
According to one aspect, the present invention which achieves these objectives relates to a method for displaying at least one image stored in an image data base connected via a network. The method comprises the steps of detecting a transmission speed of the network, and displaying at least one image stored in the image data base with a resolution corresponding to the transmission speed.
According to another aspect, the present invention which achieves these objectives relates to a device for displaying at least one image stored in an image data base connected via a network. The device comprises speed detection means for detecting a transmission speed of the network, and display means for displaying at least one image stored in the image data base with a resolution corresponding to the transmission speed.
According to still another aspect, the present invention which achieves these objectives relates to a method for communicating at least one image stored in an image data base connected via a network. The method comprises the steps of detecting a transmission speed of the network, and communicating at least one image stored in the image data base with a resolution corresponding to the transmission speed.
According to yet another aspect, the present invention which achieves these objectives relates to an apparatus for communicating at least one image stored in an image data base connected via a network. The apparatus comprises speed detection means for detecting a transmission speed of the network, and communication means for communicating at least one image stored in the image data base with a resolution corresponding to the transmission speed.
The foregoing and other objects, advantages and features of the present invention will become more apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings.